The Avengers run in The Green River Collection contains 66 books, including a straight run from issue #1 to issue #49 and the first Avengers Annual. There are two copies of issue #19, four copies of issue #20, four copies of issue #21, six copies of issue #22, and two (not including a lower-grade 5.0 copy I discoverd on ComicLink) copies of issue #23. There are also two copies each of issues #41, 42, and 44, for a grand total of 66 books.
Last updated on August 9, 2009 with the addition of scans generously donated by Mike Marianacci and Steve Colagiuri. Thank you gentlemen!